In a manufacturing process of a liquid crystal panel, a substrate where a process at a previous stage is completed needs to be transferred to a process at a next stage by a cassette. Generally, a size of a glass substrate is fixed in a specific process, and at the moment, a size of the cassette for transferring the substrate is also fixed. However, in actual production, according to market requirements, display panels with different sizes will be produced and liquid crystal panels with different sizes need to be cut to. In order to transfer the liquid crystal panels to the next process, cassettes with different sizes need to be prepared, which will occupy more space, increase production cost and reduce production efficiency.